Rotary pump



March 6, 1956 M. BITZER 2,737,341

ROTARY PUMP Filed Feb. 25, 1950 2 Sheets-Sheet 1 INVENTOR. Mam/77 5122a" /Z BY March 6, 1956 I M. BITZER 2,737,341

ROTARY. PUMP Filed Feb. 25, 1950 2 Sheets-Shem 2 IN V EN TOR. Mart/n Bltzer A TTORNEKY United States Patent 9 ROTARY PUMP Martin Bitzer, Kenmore, N. Y., assignor to Trice Products Corporation, Buffalo, N. Y.

Application February 25, 1950, Serial No. 146,264

7 Claims. (Cl. 230-153) This invention relates to the pump art and more particularly to the rotary pump field, the primary object of the invention being to provide a rotary pump of a practical nature which is efiicient under the hard usage to which it may be subjected in the automotive field.

In the automotive accessory art it has been proposed to incorporate an engine driven suction pump for the operation of accessories, and to utilize the pump as a means for ventilating the crank case of the engine power plant whether the accessory is in use or not. Due to the high rate of speed at which rotary pumps are driven, it is necessary to maintain the moving parts well lubricated for liquid sealing the clearances therebetween, and with this thought in mind it is a further and important object of this invention to provide a unique and simple construction by which the pump is effectively sealed by the lubricant to minimize the leakage of air past the moving parts to make it adequate. Again, the invention aims to improve the ventilating system.

The foregoing and other objects will manifest themselves as the following description progresses, reference being had therein to the accompanying drawings, wherein Fig. 1 is a diagrammatic view depicting the general lay out of an accessory system associated with a vehicle power plant, the vehicle being shown in'phantom;

Fig. 2 is a fragmentary view depicting the improved pump in elevation;

Fig. 3 is a cross sectional view taken about on line 3-3 of Fig. 2;

Fig. 4 is an inside view of the pump with the end wall plate removed;

Fig. 5 is an enlarged fragmentary sectional view showing more clearly the manner of effecting the oil seal;

Fig. 6 is a fragmentary perspective of the oil pump plate showing the oil flow passage therein;

Fig. 7 is a fragmentary-view of the oil pump showing the oil passage in relation thereto;

Fig. 8 is a view similar to Fig. 2, but of a modified pump; I V v Fig. 9 is a cross sectional view taken about on line 9-9 of Fig. 8; i

Fig. 10 is a detailed cross sectional view about on line 1010 of Fig. 8; and

Fig. 11 is a perspective view of a sealing gasket employed in the modified pump construction. 7

Referring more particularly to the accompanying drawings, the numeral 1 designates the internal combustion engine powerplant of a vehicle, 2 an accessory therefor, depicted by way of example as a windshield cleaner, and 3 the suction conduit connecting the accessory to the pump 4 as a source of suction. Fig. 3 shows the suction pump mounted on the oil pump 5 which latter has the usual intermeshing gears 6. with one of them keyed to the shaft 7 in turn driven from'the engine cam shaft 8 through the Worm and worm gear transmission 9. In effecting this mounting of the suction pump, the outer wall of the oil pump is replaced by a mounting plate 10 which closes the pump chamber 12 and is anchored in place by one or more screws 11.

The casing of the suction pump has a substantially circular chamber 13 in which is eccentrically arranged a rotor 14 that'has journal support on a fixed stub shaft 15. The rotor is provided with peripheral pockets 17 in which are radially slidable the blades or vanes 18 spaced apart by an intervening spring 19 on a guiding rod or spacer 19' to insure each blade following the inner contour of the rotor chamber 13 as the companion blade recedes within its pocket 17. The pump casing and the rotor 14 may be of die cast construction, while the blades themselves may be formed of a graphite-containing compound, or other suitable material. As illustrated, the casing may be cup shaped with the bottom of the cup constituting the outer end wall 20 of the suction pump chamber. The inner end wall of the chamber is in the form of a disk 21 which seats upon a gasket 22 superimposed upon the mounting plate 10. Suitable fasteners 23 passing through the flange 24 ot' the pump-casing as well as the mounting plate 10, the gasket 22, and the end wall plate or disk 21 serve to unite the parts in a tight assemblage and provide a firm mounting for the suction pump on the oil pump, while at the same time giving ready access to both the suction pump and the oil pump when desired.

The rotor 14 is driven from the oil pump shaft 7, the connection being established by a detachable coupling pin 25 which has its opposite ends non-circular in shape, such as the hexagon shape illustrated, and fitted within similarly shaped sockets in the pump shaft7 and in the end wall of the rotor 14. Since the rotor is die cast from a light alloy, it is preferable to have the socket 26, Fig. 4, formed in a wear ring 27 of a relatively harder metal and of a larger diameter to give a better supporting surface for the driving pin 25 upon the rotor. Further, this drive connection may incorporate a slight amount of play to accommodate slight misplacement of the rotor with respect to the axis of shaft 7.

Oil is admitted into the oil pump from the crank case through a pipe 28 and is forced out to the various bearings of the engine in the usual manner. The suction pump is provided with an inlet passage 29 and an outlet passage 30 opening into the pump chamber 13 in the form of arcuate shaped ports at opposite sides of the area of oil-sealed contact between the periphery of the rotor and the inner cylindrical wall of the chamber 13, as indicated at 31, Fig. 4. Oil is supplied the suction pump under pressure by the oil pump through a small hole 38 formed in the mounting plate, and from this hole an oil groove'39 leads to an oil hole 40 formed in the end wall plate 21 of the suction pump, the location of the hole 40 being preferably in opposition to the inlet port 29 so that the suction or low pressure in the suction pump will assist the oil flow from the oil pump for purposes of adequate lubrication.

The accessory suction line 3 is connected to the inlet passage 29, while the discharge from the outlet port 30 is inwardly through a radial passage 32 of the end wall 20 and through an axial bore 33 in the stub shaft 15. From thence the oil passes through the axial bore 34 in the coupling pin 25 and out through the axial bore 35 of the oil pump shaft 7 into the crank case, and since this path of flow also constitutes the air discharge course, the discharged 'air will circulate through the crank case and ventilate it before emerging to the outer atmosphere by provided passages for such purpose. The stub shaft 15 is provided with radial openings 36 leading from the bore 33 and by which the journal support for the rotor is well lubricated. The rotor body is provided with oil conducting passages 37 opening out into the blade pockets 17 so as to insure adequate lubrication for the blades in their in and out movements.

The foregoing provides a suction pump structure which is, kept well lubricated. to insure durability and. efliciency in operation. The oil which passes into the suction pump through the hole 49 will gradually spread out over the surfaces of the moving parts,including eudi Walls of the rotor across which the gaseous fluid tends to escape from the high pressure or" outlet side of the pump to the inlet side thereof. To resist thisleakage means are provided for building up and maintaining an effective oil seal around the outer margins of the end walls, as indicated M41 in Fig. 5.

According to the present invention, this is accomplished herein by providing the end walls of the rotor with an annular series. of radial: grooves 42 which terminate short of the outer margin of the end walls thereby to form a ring-like surface area 43' about the outer ends of the grooves 42 uninterrupted except by' the blade pockets 17. The inner ends of the: groove stop short of the wear ring 27. The function of these. grooves 42 is to guide the oil outwardly onto this uninterrupted area 43 under the centrifugal action of the rotor. The air pressure at the outlet side of the pump will tend to escape across the end walls of the rotor, but thiSz path of escape is blocked by the oil sealwhich is continually being fed by the outwardly flowing oil under the centrifugal urge and the direction of the oil flow grooves 42. The result is an eliective barricade against the escape of air across the end walls, with a consequential higher vacuum being developed.

In the embodiment shown in Figs. 8 through 11, the

suction pump is mounted directly on the front wall 44 of the crank case, the sealing gasket 22 and the removable end wall 21 being interposed between the pump casing 4' and the engine block where it is secured by the anchoring fasteners 23'. In this embodiment the sealing liquid is supplied from. an oil pressure supply pump (not shown) through an axial passage 45 in the cam shaft 46 where it flows about the coupling. pin 25 into the chamber 47 of the rotor 14. From this chamber 47 the oil passes out through the ports 37 and 36 for lubricating the rotor and its sliding vanes. Other oil will pass downwardly through agroove 48 in the form of a slot in the gasket 22, such additional oil passing into the pump chamber through a small orifice 40' in the region of the intake side of the pump.

In mounting the pump, the cam shaft 46 of the vehicle power plant is fitted with an extension 49 to adapt the shaft for receiving the adjacent end of the coupling pin 25. The discharge from the pump is made through the outlet. port 30' and a registering opening 50 in the crank case wall .44 directly into the crank case. As in the first embodiment, the end walls of. the rotor are formed with the oil directing grooves or channels 42 for building up and maintaining. a sealing ring on. the uninterrupted area 43;

From. the foregoing it will be observed that the pump is readily'dissembled andis easily maintained well lubricated for: high speed use. By reason. of the elfective seal on the outer margin of the end walls of the rotor, the air slippage from; one side to the other side of the rotor is precluded to a practical extent. This enables the generation of a high suction for the operation of the automotive accessory and. also affords a generous ventilating airflow through the crank case. When the use of the accessory has been discontinued, the suction line 3 will. be opened .to the. atmosphere through a valve 51 which may be opened. either manually orautomatically. An example wells joined by a substantially circular wall to define a eh mben. inlet an outlet ports for he h mb rn r tor journaled eccentrically in the chamber in oil sealed contact with the circular wall between the ports and having its opposite end walls in oil sealed contact with the chamber end walls, the periphery of the rotor having blade receiving pockets therein opening through its end walls, passage means supplying oil to end walls and to the pockets, blades slidable in the pockets for following the circular wall of the chamber to constitute impeller means, and a series of radial grooves of substantially uniform length formed in the opposite end walls of the rotor and terminating short of their outer margins to leave an annular uninterrupted surface area on the end walls extending from the grooves to the periphery of the rotor onto which the sealing oil is thrown outwardly by centrifugal action for maintaining a sealing ring of oil uninterrupted except by the pockets, the groove extending inwardly short of the full inward extent of the pockets.

2'. A rotary pump comprising a casing havinga chamber:

with opposing end walls joined by a substantially circular wall, inlet and, outlet ports for the chamber, a stub shaft fixed on one end wall, a rotor eccentrically journaled in the chamber on the stub shaft to have oil sealed contact with the circular wall between the ports and formed with peripheral pockets: opening through its opposite end walls said end walls being in oil sealed. contact with the chamber end walls; one of the chamber end walls being formed with an oil supply passage blades on the rotor within the, pockets; thereof, and. outwardly extending grooves of uniform length in the opposite end walls of. the. rotor serving centrifugally to direct the sealing oil outwardly to form and maintain a sealing ring of oil at the outer margins of the end walls, the pockets opening through the end walls of the rotor inwardly beyond the grooves, and the outer ends of the grooves terminating short of the outer margin of the end walls to leave acontinuous annular area for receiving a sealing ring of oil thereabout.

3. A rotary pump comprising a casing having a substantially' circular chamber with inlet and outlet ports, a rotor journaled eccentrically in the chamber and having its opposite end walls in oil sealed contact with end walls of the chamber, an oil supply passage opening through one end wall of the chamber against the adjacent end wall of the rotor, and impelling blades carried by the rotor in blade pockets therein opening through the rotor end walls, the opposite end walls of the rotor having outwardly extending oil carrying grooves extending radially for a major portion of the length of the pockets from a point adjacent the inner ends of the pockets and terminating short of the peripheries of the rotor end walls and serving centrifugally to maintain a continuous sealing. ring of oil at the outer margins of the end walls outwardly of the grooves.

4.. A. rotary pump comprising a casing having a stub shaft provided with an axial bore opening through one end thereof, the casing having inlet and outlet ports, a rotor journaled on the stub shaft and having radial pockets communicating with an axial passage in the rotor into which passage the open end of the shaft discharges, the end walls of the rotor having radial grooves for conveying sealing oil outwardly toward the margins thereof, blades slidably mounted in the pockets, passage means leading to and supplying lubricant to the axial bore of the shaft and therethrough to the pockets for lubricating the blades with the lubricant being free to flow out of the pockets onto the end. walls of the rotor, a drive shaft coaxial with the rotor and having an axial bore noncircular in cross, section, a wear ring secured in the rotor passage and likewise having a bore, non-circular in cross section, and a connector pin drivingly engaged in the two bores of non-circular cross section and itself formed with a through passage connecting the two bores for lubricant flow. 5'. A rotary pump comprising a casing having a tubular stub shaft fixed in one end wall thereof, said stub shaft being provided with an axial bore and a radial opening through its periphery, a drive shaft arranged coaxial of the stub shaft and having an axial bore, a rotor journaled on the stub shaft and overlying the radial opening, said rotor having oppositely extending radial pockets opening through its end walls and also having radial openings establishing communication between the pockets and the stub shaft, the casing having inlet and outlet ports, passage means supplying lubricant to the stub shaft bore for outward flow through the radial opening of the shaft and also into the pockets, blades slidably mounted in the pockets and projecting outwardly therefrom, a spacer interposed between the blades and moving back and forth through the radial openings, and a coupling member coaxial with the drive shaft and the rotor and having a through lubricant passage establishing flow communication bewteen the two bores.

6. A rotary pump comprising a casing having a chamber with opposing end walls joined by a substantially circular wall, inlet and outlet ports for the chamber, a fixed rotor shaft solidly mounted on one end wall to provide a single bearing, a rotor journaled on the bearing and eccentrically arranged in the chamber in oil sealed contact with the circular wall between the ports, the opposite ends of the rotor being in oil sealed contact with the chamber end walls, said rotor having a recessed portion in one end opposing the other end wall, a floating drive shaft engaging in the recessed portion and passing through the other end wall unsupported thereby for connection to a power drive, and oil supply means connected to the rotor shaft bearing.

7. A vehicle power plant comprising an internal oombustion engine having a crank case with a shaft journaled in one wall thereof, a rotary pump having a casing with a rotor and a pair of vanes therein, said casing having end walls joined by a circular wall and secured to the outer wall surface of the crank case over the end of the shaft, the shaft and the rotor having axially aligned sockets, a coupling pin extending freely through one end wall and the crank case wall and engaged loosely in the sockets to operatively connect the shaft to the rotor, and a rotor supporting shaft fixed to the other end wall of the casing to provide a single solid mounting for the rotor, said rotor shaft serving to position the rotor eccentrically in said pump casing and being interlocked with said other end wall and integral therewith.

References Cited in the file of this patent UNITED STATES PATENTS 34,318 Smith Feb. 4, 1862 845,114 Palmer Feb. 26, 1907 1,379,248 Carrey May 24, 1921 1,451,859 Balcker Apr. 17, 1923 1,635,006 Oliver July 5, 1927 1,675,686 Barnes July 3, 1928 1,977,109 Badger Oct. 16, 1934 2,035,096 Schneider Mar. 24, 1936 2,230,594 Horton Feb. 4, 1941 2,504,841 Jones Apr. 18, 1950 

